/*
 * An hwmon driver for the 3Y Power YM-2651Y Power Module
 *
 * Copyright (C) 2014 Accton Technology Corporation.
 * Brandon Chuang <brandon_chuang@accton.com.tw>
 *
 * Based on ad7414.c
 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#if 0
#define DEBUG
#endif

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>

#define MAX_FAN_DUTY_CYCLE 100

/* Addresses scanned
 */
static const unsigned short normal_i2c[] = { I2C_CLIENT_END };

enum chips {
	YM2651,
	YM2401,
};

/* Each client has this additional data
 */
struct ym2651y_data {
	struct device	  *hwmon_dev;
	struct mutex		update_lock;
	char				valid;		   /* !=0 if registers are valid */
	unsigned long	   last_updated;	/* In jiffies */
	u8	 chip;			/* chip id */
	u8   capability;	 /* Register value */
	u16  status_word;	/* Register value */
	u8   fan_fault;	  /* Register value */
	u8   over_temp;	  /* Register value */
	u16  v_out;		  /* Register value */
	u16  i_out;		  /* Register value */
	u16  p_out;		  /* Register value */
	u8   vout_mode;		/* Register value */
	u16  temp;		   /* Register value */
	u16  fan_speed;	  /* Register value */
	u16  fan_duty_cycle[2];  /* Register value */
	u8   fan_dir[5];	 /* Register value */
	u8   pmbus_revision; /* Register value */
	u8   mfr_id[10];	 /* Register value */
	u8   mfr_model[16]; /* Register value */
	u8   mfr_revsion[3]; /* Register value */
	u16  mfr_vin_min;	/* Register value */
	u16  mfr_vin_max;	/* Register value */
	u16  mfr_iin_max;	/* Register value */
	u16  mfr_iout_max;   /* Register value */
	u16  mfr_pin_max;	/* Register value */
	u16  mfr_pout_max;   /* Register value */
	u16  mfr_vout_min;   /* Register value */
	u16  mfr_vout_max;   /* Register value */
};

static ssize_t show_byte(struct device *dev, struct device_attribute *da,
			 char *buf);
static ssize_t show_word(struct device *dev, struct device_attribute *da,
			 char *buf);
static ssize_t show_linear(struct device *dev, struct device_attribute *da,
			 char *buf);
static ssize_t show_vout(struct device *dev, struct device_attribute *da, char *buf);
static ssize_t show_fan_fault(struct device *dev, struct device_attribute *da,
			 char *buf);
static ssize_t show_over_temp(struct device *dev, struct device_attribute *da,
			 char *buf);
static ssize_t show_ascii(struct device *dev, struct device_attribute *da,
			 char *buf);
static struct ym2651y_data *ym2651y_update_device(struct device *dev);
static ssize_t set_fan_duty_cycle(struct device *dev, struct device_attribute *da,
			 const char *buf, size_t count);
static int ym2651y_write_word(struct i2c_client *client, u8 reg, u16 value);

enum ym2651y_sysfs_attributes {
	PSU_POWER_ON = 0,
	PSU_TEMP_FAULT,
	PSU_POWER_GOOD,
	PSU_FAN1_FAULT,
	PSU_FAN_DIRECTION,
	PSU_OVER_TEMP,
	PSU_V_OUT,
	PSU_I_OUT,
	PSU_P_OUT,
	PSU_TEMP1_INPUT,
	PSU_FAN1_SPEED,
	PSU_FAN1_DUTY_CYCLE,
	PSU_PMBUS_REVISION,
	PSU_MFR_ID,
	PSU_MFR_MODEL,
	PSU_MFR_REVISION,
	PSU_MFR_VIN_MIN,
	PSU_MFR_VIN_MAX,
	PSU_MFR_VOUT_MIN,
	PSU_MFR_VOUT_MAX,
	PSU_MFR_IIN_MAX,
	PSU_MFR_IOUT_MAX,
	PSU_MFR_PIN_MAX,
	PSU_MFR_POUT_MAX
};

/* sysfs attributes for hwmon
 */
static SENSOR_DEVICE_ATTR(psu_power_on,		S_IRUGO, show_word,	  NULL, PSU_POWER_ON);
static SENSOR_DEVICE_ATTR(psu_temp_fault,  	S_IRUGO, show_word,	  NULL, PSU_TEMP_FAULT);
static SENSOR_DEVICE_ATTR(psu_power_good,  	S_IRUGO, show_word,	  NULL, PSU_POWER_GOOD);
static SENSOR_DEVICE_ATTR(psu_fan1_fault,  	S_IRUGO, show_fan_fault, NULL, PSU_FAN1_FAULT);
static SENSOR_DEVICE_ATTR(psu_over_temp,   	S_IRUGO, show_over_temp, NULL, PSU_OVER_TEMP);
static SENSOR_DEVICE_ATTR(psu_v_out,	   	S_IRUGO, show_vout,		NULL, PSU_V_OUT);
static SENSOR_DEVICE_ATTR(psu_i_out,	   	S_IRUGO, show_linear,	NULL, PSU_I_OUT);
static SENSOR_DEVICE_ATTR(psu_p_out,		S_IRUGO, show_linear,	NULL, PSU_P_OUT);
static SENSOR_DEVICE_ATTR(psu_temp1_input, 	S_IRUGO, show_linear,	NULL, PSU_TEMP1_INPUT);
static SENSOR_DEVICE_ATTR(psu_fan1_speed_rpm, S_IRUGO, show_linear, NULL, PSU_FAN1_SPEED);
static SENSOR_DEVICE_ATTR(psu_fan1_duty_cycle_percentage, S_IWUSR | S_IRUGO, show_linear, set_fan_duty_cycle, PSU_FAN1_DUTY_CYCLE);
static SENSOR_DEVICE_ATTR(psu_fan_dir,	 	 S_IRUGO, show_ascii,	 NULL, PSU_FAN_DIRECTION);
static SENSOR_DEVICE_ATTR(psu_pmbus_revision,S_IRUGO, show_byte,   NULL, PSU_PMBUS_REVISION);
static SENSOR_DEVICE_ATTR(psu_mfr_id,		S_IRUGO, show_ascii,  NULL, PSU_MFR_ID);
static SENSOR_DEVICE_ATTR(psu_mfr_model,	S_IRUGO, show_ascii,  NULL, PSU_MFR_MODEL);
static SENSOR_DEVICE_ATTR(psu_mfr_revision,	S_IRUGO, show_ascii, NULL, PSU_MFR_REVISION);
static SENSOR_DEVICE_ATTR(psu_mfr_vin_min,	S_IRUGO, show_linear, NULL, PSU_MFR_VIN_MIN);
static SENSOR_DEVICE_ATTR(psu_mfr_vin_max,	S_IRUGO, show_linear, NULL, PSU_MFR_VIN_MAX);
static SENSOR_DEVICE_ATTR(psu_mfr_vout_min,	S_IRUGO, show_linear, NULL, PSU_MFR_VOUT_MIN);
static SENSOR_DEVICE_ATTR(psu_mfr_vout_max,	S_IRUGO, show_linear, NULL, PSU_MFR_VOUT_MAX);
static SENSOR_DEVICE_ATTR(psu_mfr_iin_max,	S_IRUGO, show_linear, NULL, PSU_MFR_IIN_MAX);
static SENSOR_DEVICE_ATTR(psu_mfr_iout_max,	S_IRUGO, show_linear, NULL, PSU_MFR_IOUT_MAX);
static SENSOR_DEVICE_ATTR(psu_mfr_pin_max,	S_IRUGO, show_linear, NULL, PSU_MFR_PIN_MAX);
static SENSOR_DEVICE_ATTR(psu_mfr_pout_max,	S_IRUGO, show_linear, NULL, PSU_MFR_POUT_MAX);

static struct attribute *ym2651y_attributes[] = {
	&sensor_dev_attr_psu_power_on.dev_attr.attr,
	&sensor_dev_attr_psu_temp_fault.dev_attr.attr,
	&sensor_dev_attr_psu_power_good.dev_attr.attr,
	&sensor_dev_attr_psu_fan1_fault.dev_attr.attr,
	&sensor_dev_attr_psu_over_temp.dev_attr.attr,
	&sensor_dev_attr_psu_v_out.dev_attr.attr,
	&sensor_dev_attr_psu_i_out.dev_attr.attr,
	&sensor_dev_attr_psu_p_out.dev_attr.attr,
	&sensor_dev_attr_psu_temp1_input.dev_attr.attr,
	&sensor_dev_attr_psu_fan1_speed_rpm.dev_attr.attr,
	&sensor_dev_attr_psu_fan1_duty_cycle_percentage.dev_attr.attr,
	&sensor_dev_attr_psu_fan_dir.dev_attr.attr,
	&sensor_dev_attr_psu_pmbus_revision.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_id.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_model.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_revision.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_vin_min.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_vin_max.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_pout_max.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_iin_max.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_pin_max.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_vout_min.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_vout_max.dev_attr.attr,
	&sensor_dev_attr_psu_mfr_iout_max.dev_attr.attr,
	NULL
};

static ssize_t show_byte(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ym2651y_data *data = ym2651y_update_device(dev);
	
	if (!data->valid) {
		return 0;
	}

	return (attr->index == PSU_PMBUS_REVISION) ? sprintf(buf, "%d\n", data->pmbus_revision) :
								 sprintf(buf, "0\n");
}

static ssize_t show_word(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ym2651y_data *data = ym2651y_update_device(dev);
	u16 status = 0;
	
	if (!data->valid) {
		return 0;
	}

	switch (attr->index) {
	case PSU_POWER_ON: /* psu_power_on, low byte bit 6 of status_word, 0=>ON, 1=>OFF */
		status = (data->status_word & 0x40) ? 0 : 1;
		break;
	case PSU_TEMP_FAULT: /* psu_temp_fault, low byte bit 2 of status_word, 0=>Normal, 1=>temp fault */
		status = (data->status_word & 0x4) >> 2;
		break;
	case PSU_POWER_GOOD: /* psu_power_good, high byte bit 3 of status_word, 0=>OK, 1=>FAIL */
		status = (data->status_word & 0x800) ? 0 : 1;
		break;
	}

	return sprintf(buf, "%d\n", status);
}

static int two_complement_to_int(u16 data, u8 valid_bit, int mask)
{
	u16  valid_data  = data & mask;
	bool is_negative = valid_data >> (valid_bit - 1);

	return is_negative ? (-(((~valid_data) & mask) + 1)) : valid_data;
}

static ssize_t set_fan_duty_cycle(struct device *dev, struct device_attribute *da,
			const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct i2c_client *client = to_i2c_client(dev);
	struct ym2651y_data *data = i2c_get_clientdata(client);
	int nr = (attr->index == PSU_FAN1_DUTY_CYCLE) ? 0 : 1;
	long speed;
	int error;

	error = kstrtol(buf, 10, &speed);
	if (error)
		return error;

	if (speed < 0 || speed > MAX_FAN_DUTY_CYCLE)
		return -EINVAL;

	mutex_lock(&data->update_lock);
	data->fan_duty_cycle[nr] = speed;
	ym2651y_write_word(client, 0x3B + nr, data->fan_duty_cycle[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_linear(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ym2651y_data *data = ym2651y_update_device(dev);

	u16 value = 0;
	int exponent, mantissa;
	int multiplier = 1000;

	if (!data->valid) {
		return 0;
	}	
	
	switch (attr->index) {
	case PSU_V_OUT:
		value = data->v_out;
		break;
	case PSU_I_OUT:
		value = data->i_out;
		break;
	case PSU_P_OUT:
		value = data->p_out;
		break;
	case PSU_TEMP1_INPUT:
		value = data->temp;
		break;
	case PSU_FAN1_SPEED:
		value = data->fan_speed;
		multiplier = 1;
		break;
	case PSU_FAN1_DUTY_CYCLE:
		value = data->fan_duty_cycle[0];
		multiplier = 1;
		break;
	case PSU_MFR_VIN_MIN:
		value = data->mfr_vin_min;
		break;
	case PSU_MFR_VIN_MAX:
		value = data->mfr_vin_max;
		break;
	case PSU_MFR_VOUT_MIN:
		value = data->mfr_vout_min;
		break;
	case PSU_MFR_VOUT_MAX:
		value = data->mfr_vout_max;
		break;
	case PSU_MFR_PIN_MAX:
		value = data->mfr_pin_max;
		break;
	case PSU_MFR_POUT_MAX:
		value = data->mfr_pout_max;
		break;
	case PSU_MFR_IOUT_MAX:
		value = data->mfr_iout_max;
		break;
	case PSU_MFR_IIN_MAX:
		value = data->mfr_iin_max;
		break;
	}

	exponent = two_complement_to_int(value >> 11, 5, 0x1f);
	mantissa = two_complement_to_int(value & 0x7ff, 11, 0x7ff);

	return (exponent >= 0) ? sprintf(buf, "%d\n", (mantissa << exponent) * multiplier) :
							 sprintf(buf, "%d\n", (mantissa * multiplier) / (1 << -exponent));
}

static ssize_t show_fan_fault(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ym2651y_data *data = ym2651y_update_device(dev);
	u8 shift;

	if (!data->valid) {
		return 0;
	}	
	
	shift = (attr->index == PSU_FAN1_FAULT) ? 7 : 6;

	return sprintf(buf, "%d\n", data->fan_fault >> shift);
}

static ssize_t show_over_temp(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct ym2651y_data *data = ym2651y_update_device(dev);

	if (!data->valid) {
		return 0;
	}	
	
	return sprintf(buf, "%d\n", data->over_temp >> 7);
}

static ssize_t show_ascii(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ym2651y_data *data = ym2651y_update_device(dev);
	u8 *ptr = NULL;

	if (!data->valid) {
		return 0;
	}	
	
	switch (attr->index) {
	case PSU_FAN_DIRECTION: /* psu_fan_dir */
		ptr = data->fan_dir + 1;  /* Skip the first byte since it is the length of string. */
		break;
	case PSU_MFR_ID: /* psu_mfr_id */
			ptr = data->mfr_id + 1; /* The first byte is the count byte of string. */;
		break;
	case PSU_MFR_MODEL: /* psu_mfr_model */
			ptr = data->mfr_model + 1; /* The first byte is the count byte of string. */
		break;
	case PSU_MFR_REVISION: /* psu_mfr_revision */
			ptr = data->mfr_revsion + 1; /* The first byte is the count byte of string. */
		break;
	default:
		return 0;
	}

	return sprintf(buf, "%s\n", ptr);
}

static ssize_t show_vout_by_mode(struct device *dev, struct device_attribute *da,
             char *buf)
{
	struct ym2651y_data *data = ym2651y_update_device(dev);
	int exponent, mantissa;
	int multiplier = 1000;

	if (!data->valid) {
		return 0;
	}

	exponent = two_complement_to_int(data->vout_mode, 5, 0x1f);
	mantissa = data->v_out;

	return (exponent > 0) ? sprintf(buf, "%d\n", (mantissa << exponent) * multiplier) :
							sprintf(buf, "%d\n", (mantissa * multiplier) / (1 << -exponent));
}

static ssize_t show_vout(struct device *dev, struct device_attribute *da,
             char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ym2651y_data *data = i2c_get_clientdata(client);

	if (data->chip == YM2401) {
		return show_vout_by_mode(dev, da, buf);
	}

	return show_linear(dev, da, buf);
}

static const struct attribute_group ym2651y_group = {
	.attrs = ym2651y_attributes,
};

static int ym2651y_probe(struct i2c_client *client,
			const struct i2c_device_id *dev_id)
{
	struct ym2651y_data *data;
	int status;

	if (!i2c_check_functionality(client->adapter,
		I2C_FUNC_SMBUS_BYTE_DATA |
		I2C_FUNC_SMBUS_WORD_DATA |
		I2C_FUNC_SMBUS_I2C_BLOCK)) {
		status = -EIO;
		goto exit;
	}

	data = kzalloc(sizeof(struct ym2651y_data), GFP_KERNEL);
	if (!data) {
		status = -ENOMEM;
		goto exit;
	}

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);
	data->chip = dev_id->driver_data;
	dev_info(&client->dev, "chip found\n");

	/* Register sysfs hooks */
	status = sysfs_create_group(&client->dev.kobj, &ym2651y_group);
	if (status) {
		goto exit_free;
	}

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		status = PTR_ERR(data->hwmon_dev);
		goto exit_remove;
	}

	dev_info(&client->dev, "%s: psu '%s'\n",
		 dev_name(data->hwmon_dev), client->name);

	return 0;

exit_remove:
	sysfs_remove_group(&client->dev.kobj, &ym2651y_group);
exit_free:
	kfree(data);
exit:

	return status;
}

static void ym2651y_remove(struct i2c_client *client)
{
	struct ym2651y_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ym2651y_group);
	kfree(data);

}

static const struct i2c_device_id ym2651y_id[] = {
	{ "ym2651", YM2651 },
	{ "ym2401", YM2401 },
	{}
};
MODULE_DEVICE_TABLE(i2c, ym2651y_id);

static struct i2c_driver ym2651y_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "ym2651",
	},
	.probe	  = ym2651y_probe,
	.remove	  = ym2651y_remove,
	.id_table = ym2651y_id,
	.address_list = normal_i2c,
};

static int ym2651y_read_byte(struct i2c_client *client, u8 reg)
{
	return i2c_smbus_read_byte_data(client, reg);
}

static int ym2651y_read_word(struct i2c_client *client, u8 reg)
{
	return i2c_smbus_read_word_data(client, reg);
}

static int ym2651y_write_word(struct i2c_client *client, u8 reg, u16 value)
{
	return i2c_smbus_write_word_data(client, reg, value);
}

static int ym2651y_read_block(struct i2c_client *client, u8 command, u8 *data,
			  int data_len)
{
	int result = i2c_smbus_read_i2c_block_data(client, command, data_len, data);

	if (unlikely(result < 0))
		goto abort;
	if (unlikely(result != data_len)) {
		result = -EIO;
		goto abort;
	}

	result = 0;

abort:
	return result;
}

struct reg_data_byte {
	u8   reg;
	u8  *value;
};

struct reg_data_word {
	u8   reg;
	u16 *value;
};

static struct ym2651y_data *ym2651y_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ym2651y_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
		|| !data->valid) {
		int i, status, length;
		u8 command, buf;
		struct reg_data_byte regs_byte[] = { {0x19, &data->capability},
											 {0x20, &data->vout_mode},
											 {0x7d, &data->over_temp},
											 {0x81, &data->fan_fault},
											 {0x98, &data->pmbus_revision}};
		struct reg_data_word regs_word[] = { {0x79, &data->status_word},
											 {0x8b, &data->v_out},
											 {0x8c, &data->i_out},
											 {0x96, &data->p_out},
											 {0x8d, &data->temp},
											 {0x3b, &(data->fan_duty_cycle[0])},
											 {0x3c, &(data->fan_duty_cycle[1])},
											 {0x90, &data->fan_speed},
											 {0xa0, &data->mfr_vin_min},
											 {0xa1, &data->mfr_vin_max},
											 {0xa2, &data->mfr_iin_max},
											 {0xa3, &data->mfr_pin_max},
											 {0xa4, &data->mfr_vout_min},
											 {0xa5, &data->mfr_vout_max},
											 {0xa6, &data->mfr_iout_max},
											 {0xa7, &data->mfr_pout_max}};

		dev_dbg(&client->dev, "Starting ym2651 update\n");
		data->valid = 0;

		/* Read byte data */
		for (i = 0; i < ARRAY_SIZE(regs_byte); i++) {
			status = ym2651y_read_byte(client, regs_byte[i].reg);

			if (status < 0) {
				dev_dbg(&client->dev, "reg %d, err %d\n",
						regs_byte[i].reg, status);
				goto exit;
			}
			else {
				*(regs_byte[i].value) = status;
			}
		}

		/* Read word data */
		for (i = 0; i < ARRAY_SIZE(regs_word); i++) {
			status = ym2651y_read_word(client, regs_word[i].reg);

			if (status < 0) {
				dev_dbg(&client->dev, "reg %d, err %d\n",
						regs_word[i].reg, status);
				goto exit;
			}
			else {
				*(regs_word[i].value) = status;
			}
		}

		/* Read fan_direction */
		command = 0xC3;
		status = ym2651y_read_block(client, command, data->fan_dir,
										 ARRAY_SIZE(data->fan_dir)-1);
		data->fan_dir[ARRAY_SIZE(data->fan_dir)-1] = '\0';

		if (status < 0) {
			dev_dbg(&client->dev, "reg %d, err %d\n", command, status);
			goto exit;
		}

		/* Read mfr_id */
		command = 0x99;
		status = ym2651y_read_block(client, command, data->mfr_id,
										 ARRAY_SIZE(data->mfr_id)-1);
		data->mfr_id[ARRAY_SIZE(data->mfr_id)-1] = '\0';

		if (status < 0) {
			dev_dbg(&client->dev, "reg %d, err %d\n", command, status);
			goto exit;
		}

		/* Read mfr_model */
		command = 0x9a;
		length  = 1;
		
		/* Read first byte to determine the length of data */
		status = ym2651y_read_block(client, command, &buf, length);
		if (status < 0) {
			dev_dbg(&client->dev, "reg %d, err %d\n", command, status);
			goto exit;
		}
		
		status = ym2651y_read_block(client, command, data->mfr_model, buf+1);
		data->mfr_model[buf+1] = '\0';

		if (status < 0) {
			dev_dbg(&client->dev, "reg %d, err %d\n", command, status);
			goto exit;
		}

		/* Read mfr_revsion */
		command = 0x9b;
		status = ym2651y_read_block(client, command, data->mfr_revsion,
										 ARRAY_SIZE(data->mfr_revsion)-1);
		data->mfr_revsion[ARRAY_SIZE(data->mfr_revsion)-1] = '\0';

		if (status < 0) {
			dev_dbg(&client->dev, "reg %d, err %d\n", command, status);
			goto exit;
		}

		data->last_updated = jiffies;
		data->valid = 1;
	}

exit:
	mutex_unlock(&data->update_lock);

	return data;
}

static int __init ym2651y_init(void)
{
	return i2c_add_driver(&ym2651y_driver);
}

static void __exit ym2651y_exit(void)
{
	i2c_del_driver(&ym2651y_driver);
}

MODULE_AUTHOR("Brandon Chuang <brandon_chuang@accton.com.tw>");
MODULE_DESCRIPTION("3Y Power YM-2651Y driver");
MODULE_LICENSE("GPL");

module_init(ym2651y_init);
module_exit(ym2651y_exit);

